Four point bearings have on their outer and inner rings two circular arc-shaped raceways whose centres of curvature are offset so that during radial loading the balls contact the raceways at four points.

Both rings posses deep grooves with a radius only slightly exceeding the ball radius. Due to this curvature ratio the bearing can support high radial forces as well as axial forces which make them ideal for a wide range of applications.

Cylindrical roller bearings

Cylindrical roller bearings have exceptionally low friction torque characteristics that make them suitable for high speed operation. They also have high radial load carrying capacity. They are typically used in machine tools, transmissions, vibration machines and as wheelset bearings for rail vehicles.

The surface finish of the tracks and rolling elements is critical to the running performance and noise characteristics of these bearings. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the surface finish characteristics of cylindrical roller bearings. For further details click the link below.

Also of critical importance is the roundness and waviness of the tracks and rolling elements. Typically these features are measured using roundness instruments, for further details click the link below.

Along with general geometrical features there is also a requirement to analyse the cross sectional shape of the bearing track and rolling elements. These typically have a crowned (barrel) type shape to avoid a build of peak stresses at the edge of the bearing.This shape can be defined in a number of ways, which includes a simple large radius or a mathematical equation. Typically the nominal profile has a defined upper and lower tolerance.

Roller bearing analysis can consist of comparing a measured profile against a nominal, upper and lower tolerance band. This analysis can be completed using special geometrical software from Taylor Hobson Ltd.

Spherical roller bearings

Most spherical bearings have an outer raceway that is a portion of a sphere and as such they are internally self-aligning. Each roller has a curved form at right angles to the direction of rotation, which conforms relatively closely to the inner and outer raceways. This gives this bearing high radial load carrying capacity. Applications for these bearings include heavy support rollers, ship line shafts and rudder shafts, crankshafts, rolling mills and grinding machines.

The surface finish of the tracks and rolling elements is critical to the running performance and noise characteristics of these bearings. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the surface finish characteristics of spherical roller bearings. For further details click the link below.

Also of critical importance is the roundness and waviness of the tracks and rolling elements. Typically these features are measured using roundness instruments, for further details click the link below.

Along with surface texture and form there is a requirement to measure and analyse a wide number of geometric features, which include the outer track radius and the flange angles. Typically the tracks and rolling elements have defined radii which minimise the build up of peak stresses at their edge and improve radial load capacity. These features can be analysed using special geometrical software from Taylor Hobson Ltd.

Taper roller bearings

The taper roller bearing has the ability to carry combinations of large radial and thrust loads or to carry thrust load only. Because of the difference between the inner and outer raceway contact angles, there is a force component, which drives the tapered rollers against the guide flange. The relatively large sliding friction generated at this flange makes this bearing typically unsuitable for high-speed applications without special consideration to coolant/lubricant. Typical applications include construction machinery, gear construction, vehicle manufacture and rolling mills.

The surface finish of the tracks and rolling elements is critical to the running performance and noise characteristics of these bearings. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the surface finish characteristics of taper roller bearings. For further details click the link below.

Also of critical importance is the roundness and waviness of the tracks and rolling elements. Typically these features are measured using roundness instruments, for further details click the link below.

Along with general geometrical features there is also a requirement to analyse the cross sectional shape of the bearing track and rolling elements. These typically have a crowned (barrel) type shape to avoid a build of peak stresses at the edge of the bearing. This shape can be defined in a number of ways, which includes a simple large radius or a mathematical equation. These shapes can be analysed using special geometrical software from Taylor Hobson Ltd.

Rolling elements

Contact rolling bearing elements come in a variety of different shapes, including spherical, cylindrical and conical (taper roller). The running performance and noise generation of bearings is to a large extent dependent on the precision of the rolling elements. Typically the surface finish characteristics of rolling elements has a greater effect on the noise generated by a bearing than the surface finish of the tracks.

The form and surface finish of rolling elements is critical to the running performance and noise characteristics of any contact roller bearing. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the form and surface finish characteristics of rolling elements. For details see the Form Talysurf links below. Also of critical importance is the roundness and waviness of the rolling elements. Typically these features are measured using roundness instruments the link below for more information.

Taylor Hobson have also developed a special fixturing device called a ball unit which can used with any Form Talysurf Inductive system to measure the surface finish of cylindrical and ball rolling elements. It works by using a friction pad to rotate a rolling element over a stationary inverted inductive gauge. The gauge range used is very small so the inductive gauge can be set to a high resolution setting and as such it can achieve very low surface finish measurements (<6nm Ra is feasible).

Hard disc drive bearings

There are fundamentally two types of hard disc drive bearings which are those based on standard contact ball bearings and those based on fluid dynamic bearings.

The form, radius and surface finish of the tracks is critical to the running performance and noise characteristics of these bearings. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the form and surface finish characteristics of hard disc drive bearings.

Fluid dynamic bearings

In fluid dynamic bearings, the bearing function is taken over by a layer of lubricant less than one tenth the thickness of a human hair. The rotor supported by the bearing essentially swims around the shaft.

The elimination of metal to metal contact in fluid dynamic bearings eliminates non-repeatable runout due to surface imperfections. This makes it possible to reduce track spacing and increase the tracks per inch on the disk.

Control of surface finish, roundness and waviness is critical to the performance of fluid dynamic bearings. However there are also typically grooves machined in the shaft and rotor of FDBs which assist in the build up of a stable lubrication layer.Through co-operation with manufacturers, Taylor Hobson has developed a special analysis tool for analysing the shape and ratio of the grooves on FDB's.

Four point bearings

Four point bearings have on their outer and inner rings two circular arc-shaped raceways whose centres of curvature are offset so that during radial loading the balls contact the raceways at four points. The contact angles of four point bearings are large (usually 35ï¿½). Therefore these bearings are capable of transmitting high axial loads in both directions.

The form, radius and surface finish of the tracks is critical to the running performance and noise characteristics of these bearings. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the form and surface finish characteristics of four point ball bearings.

Also of critical importance is the roundness and waviness of the races and rolling elements. Typically these features are measured using roundness instruments as detailed in the Talyrond links below.

Wall Thickness and Gothic Arch Analysis

Along with general geometrical features there is also typically a requirement to look at other critical factors which affect the running performance of these bearings. One of the important factors in ball bearing running performance is Wall Thickness Variation. While another critical factor is the relationship of the two arcs on the inner race to each other. Taylor Hobson have developed a dedicated analysis software for analysing both these features. For further details contact your local sales representative.

Angular contact ball bearings

Angular contact ball bearings are designed to support combined radial and thrust loads or heavy thrust loads depending on the contact angle magnitude. The bearings having large contact angles can support heavier thrust loads. They are suitable for a wide range of applications including high speed machine tool spindles.

The form, radius and surface finish of the tracks is critical to the running performance and noise characteristics of these bearings. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the form and surface finish characteristics of angular contact ball bearings. For further information click the link below.

Also of critical importance is the roundness and waviness of the races and rolling elements. Typically these features are measured using roundness instruments as detailed in the Talyrond links below.

Wall Thickness Variation

Along with general geometrical features there is also typically a requirement to look at other critical factors which affect the running performance of these bearings. One of the important factors in ball bearing running performance is Wall Thickness Variation. In particular for bearings that are fixed within a housing the wall thickness variation of the inner ring is critical while for bearings located on a shaft the wall thickness variation of the outer ring is critical. Taylor Hobson have dedicated analysis software for measuring wall thickness variation of ball bearing races. For further details contact your local sales representative.

Deep groove ball bearings

Both rings posses deep grooves with a radius only slightly exceeding the ball radius. Due to this curvature ratio the bearing can support high radial forces as well as axial forces which make them ideal for a wide range of applications.

The form, radius and surface finish of the tracks is critical to the running performance and noise characteristics of these bearings. Taylor Hobson have a range of Form Talysurf systems which are suitable for measuring the form and surface finish characteristics of deep groove ball bearings. For product details click the link below.

Also of critical importance is the roundness and waviness of the races and rolling elements. Typically these features are measured using roundness instruments, for product information click the link below

Wall Thickness Variation

Along with general geometrical features there is also typically a requirement to look at other critical factors which affect the running performance of these bearings. One of the important factors in ball bearing running performance is Wall Thickness Variation. In particular for bearings that are fixed within a housing the wall thickness variation of the inner ring is critical while for bearings located on a shaft the wall thickness variation of the outer ring is critical. Taylor Hobson have dedicated analysis software for measuring wall thickness variation of ball bearing races. For further details click the link below.